When you first become eligible for Medicare, you’re enrolling in Original Medicare (Part A and Part B), the government-run health-care program for those 65 and older and certain individuals who qualify by disability or having end-stage renal disease (ESRD) or amyotrophic lateral sclerosis (Lou Gehrig’s disease).

Medicare enrollment periods for Original Medicare

There are three periods in which you can manually enroll in Medicare Par A and/or Part B:

Initial Enrollment Period (IEP) — When you are first eligible for Medicare, you have a seven-month period to sign up. This seven-month period begins three months before your 65th birthday, includes the month you turn 65, and ends three months after you turn 65. If you qualify because you’re receiving disability benefits, it starts three months before your 25th month of disability benefits from the Social Security Administration (SSA) or Railroad Retirement Board (RRB) and lasts seven months
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General Enrollment Period (GEP) — If you miss your Initial Enrollment Period, you can sign up between January 1 through March 31 each year. Your coverage will begin July 1. You may have to pay a late-enrollment period in the form of a higher premium for Part A and/or Part B.

Special Enrollment Period (SEP) — If you or your spouse (or family member if you are disabled) is currently working and you are covered by employer or union-sponsored health insurance, you will have a Special Enrollment Period when your coverage ends, or you stop working (whichever happens first), up to two full months after the month your coverage ends. You may also be eligible for a Special Enrollment Period in other situations. For example, if you are serving as an international volunteer for a tax-exempt organization and have other health coverage, you may get an SEP when you return to the United States.